# -*- coding:utf-8 -*-
class Solution:
    # 栈先进后出，所有操作均在栈顶；队列先进先出
    def __init__(self):
        self.stacktolist = []
    def push(self, node):
        if len(self.stacktolist):
            self.stacktolist = [node] + self.stacktolist[:]
        else:
            self.stacktolist.append(node)
        # write code here

    def pop(self):

        # return xx
        return self.stacktolist.pop()